Go with being the son of a disabled veteran which has raised your awareness of people with disabilities and inspired you to work with veterans as well as teens with disabilities.
The fact that they are in your primary doesn't matter, in some cases someone will look at the diversity prompt in the absence of the primary application. That you put it on the AMCAS application confirms that you are sincere with this as an important part of your life.
I think the bigger issue here is that you really needed to think about this. There are going to be a lot of other applicants out there who know the answer to this question right away.
There is a great video online from Kaplan where they interview the Dean of Admissions at Hopkins and he really makes it clear that the answer to a question such as this should have some depth to it. I don't think the examples you used will demonstrate that depth. He actually used an example similar to your #2 idea and said that is an explanation that he would not be impressed with.
You really should think about this more thoroughly.